CVE-2026-24061 GNU inetutils Telnet Detector

A safe, passive detection tool for identifying potential exposure to CVE-2026-24061, a vulnerability affecting certain versions of GNU inetutils telnet.

This project is designed for DevOps pipelines, infrastructure audits, and defensive security portfolios.

What is CVE-2026-24061?

CVE-2026-24061 is a vulnerability affecting specific versions of GNU inetutils telnet. Systems running affected versions may be at risk if the telnet client or service is installed and accessible.

This tool does not exploit the vulnerability.

Affected Versions

Impact

Affected versions of GNU inetutils telnet may allow unauthorized access under certain conditions. Systems running vulnerable versions should be updated or have telnet removed if not required.

What this tool does

✔ Detects presence of telnet
✔ Identifies GNU inetutils implementation
✔ Extracts installed version
✔ Flags versions in the vulnerable range
✔ Produces human-readable and JSON output
✔ Supports CI/CD exit codes

What this tool does NOT do

✘ No exploitation
✘ No fuzzing
✘ No malformed network traffic
✘ No service interaction

This is read-only detection only.

Usage

python3 inetutils-telnet-cve-2026-24061-check.py

JSON output (for pipelines)

python3 inetutils-telnet-cve-2026-24061-check.py --json

CI/CD Integration

This tool can be run automatically in your pipelines. For example, in GitHub Actions:

name: CVE-2026-24061 Check

on: [push, pull_request]

jobs:
  security-check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Run CVE-2026-24061 detector
        run: |
          python3 inetutils-telnet-cve-2026-24061-check.py --json

The script exits with a non-zero status if a vulnerable version of GNU inetutils telnet is detected, allowing pipelines to fail automatically. JSON output is also produced for logging or reporting.

Example Outputs

Not vulnerable

CVE-2026-24061 Telnet Exposure Check
-----------------------------------
host                     : ci-runner-01
telnet_present           : True
implementation           : GNU inetutils telnet
version                  : 2.8
vulnerability_status     : not_vulnerable
recommended_action       : none

Vulnerable

CVE-2026-24061 Telnet Exposure Check
-----------------------------------
host                     : prod-web-02
telnet_present           : True
implementation           : GNU inetutils telnet
version                  : 2.5
vulnerability_status     : vulnerable
recommended_action       : Upgrade inetutils to a non-vulnerable version or remove/disable telnet service entirely.

Indeterminate

CVE-2026-24061 Telnet Exposure Check
-----------------------------------
host                     : legacy-host
telnet_present           : True
implementation           : None
version                  : None
vulnerability_status     : indeterminate
recommended_action       : Verify telnet implementation and version manually; consider removal if not required.

Remediation Guidance

If the system is detected as vulnerable:

1. Remove Telnet (preferred)

The safest option is to remove the telnet client entirely:

Ubuntu / Debian

sudo apt remove telnet -y
sudo apt autoremove -y

RHEL / CentOS / Fedora

sudo dnf remove telnet -y

Arch Linux

On Arch Linux, telnet is bundled within inetutils, which provides essential tools like ping and hostname. Removing inetutils is not recommended.

Safe alternative to mitigate risk is stop and disable the telnet server if it is running:

sudo systemctl stop telnet.socket
sudo systemctl disable telnet.socket

2. Upgrade Telnet (if removal is not possible)

Many Linux distributions still ship older binaries, so upgrading via package manager may not resolve the vulnerability. If telnet must remain, consider:

• Building GNU inetutils ≥ 2.8 from source
• Running telnet in a restricted or containerized environment
• Restricting telnet network access using firewalls or access controls